It is conventional to employ continuous wave laser systems for ophthalmic surgery and other medical applications. However, conventional continuous wave laser systems have produced large amounts of waste heat when used in such applications, and for this reason have employed external cooling water supplies (or other external cooling means) to dissipate waste heat.
Some conventional continuous wave laser systems have employed mechanical shuttering devices in the laser beam path to convert the laser output beam mechanically into a pulsed output beam. However, such mechanical shuttering devices are slow, and typically produce audible clicking noises whenever the user actuates the system, which undesirably tends to cause the patient being treated to flinch.
The present invention employs electronic switching to produce a pulsed laser output beam (for ophthalmic and other medical applications) in a silent and efficient manner, without moving mechanical parts, and in a manner reducing the laser system's duty cycle (and hence the time-averaged heat generated by the system). The inventive electronic pulsing circuitry is also much faster (i.e., results in much shorter pulse rise times) than mechanical beam chopping means. Furthermore, the inventive electronic pulsing technique allows the laser system to operate with a self-contained, internal cooling means, so that the system does not require external water connections and is portable.
Another important advantage of the electronic pulsing circuitry of the invention is that it accepts standard, 115-120 volt, AC power from a wall outlet, and converts such standard power to a pulse (having controlled duration and amplitude) for powering a laser. The ability to accept power from a standard wall outlet is useful, in that it enables the inventive apparatus to be moved conveniently between treatment rooms (for use in any of the rooms), without the expense and inconvenience of installing special wiring.